Lightning is Salesforce’s reimagined UI that is a responsive mobile-first type UI based on the Aura framework. Salesforce Lightning also encompasses the tools and technologies behind the new UI-like Lightning Connect, Lightning App Builder, Lightning Component Framework and Lightning Design System. Here’s what I love about it, to start:

The new Lightning UI , what Salesforce calls the Lightning Experience, is a modern UI that brings Salesforce into the responsive UI era of web-based applications and will allow Salesforce to have a common UI across any device in the not-so-distant future. The classic Salesforce UI was and still is very functional and based off of best practices prior to HTML5 and responsive UI and mobile-first design becoming the norm.

It was a big undertaking by Salesforce to totally redesign their front end, and at the same time still support all of the existing functionality and customization that customers have built on the platform. Visualforce pages will still work with Lightning and you can even build Lightning Components to use on Visualforce pages.

With tools like Lightning App Builder, Salesforce is making it even easier to build applications on top of their platform. Lightning apps can built as standalone apps or on top of existing Salesforce applications or Salesforce1 mobile applications. Lightning components can be built and also pulled into your org from the Appexchange for Components.

Lightning components can also be used in the Community Builder, and the new consumer-based UI can be used instead of having to use other frameworks (like Bootstrap) that aren’t native to the Salesforce platfrom to make your external facing web presence modern and responsive. Some companies and organizations already had to go away from standard Salesforce UI for those scenarios but can now make use of Lightning for those needs to stay within the platform.

With the Lightning Design system, UI designers and developers can create pixel-perfect designs and applications for a very professional and polished user experience. Salesforce provides a UI library and their CSS framework as well as best practices guides to help get started with designing.

To learn Lightning and how to build apps with Lightning , Salesforce has provided free training and tutorials through Trailhead, and even though it’s on the developer site, the training sessions are segmented and geared towards all types of users, salespeople, administrators and developers. Going through Trailhead you can set up a development org with Lightning to try it out and try your hand at building apps or designing a Lightning page or component.